limonite
noun
li·mo·nite ˈlī-mə-ˌnīt 
: a native hydrous ferric oxide of variable composition that is an ore of iron
limonitic
ˌlī-mə-ˈni-tik
adjective 
Example Sentences
Recent Examples on the Web Red areas are due to rust mixtures, yellows are due to iron sulfide, purples are from goethite or oxidized limonite, and the greens come from chlorite. 
Stacey Leasca, Travel + Leisure, 12 May 2022 Researchers believe that may have been the result of a limonite particle being present in the stone at that location. David Kindy, Smithsonian Magazine, 31 Mar. 2022 The Jie Shun’s manifest listed its only cargo as limonite, a kind of iron ore. Washington Post, 26 Oct. 2019 At first, the cargo hold appeared to match the description on the manifest: 2,300 tons of loose yellow rocks called limonite, a kind of iron ore. Author: Joby Warrick, Alaska Dispatch News, 2 Oct. 2017
Stacey Leasca, Travel + Leisure, 12 May 2022 Researchers believe that may have been the result of a limonite particle being present in the stone at that location. David Kindy, Smithsonian Magazine, 31 Mar. 2022 The Jie Shun’s manifest listed its only cargo as limonite, a kind of iron ore. Washington Post, 26 Oct. 2019 At first, the cargo hold appeared to match the description on the manifest: 2,300 tons of loose yellow rocks called limonite, a kind of iron ore. Author: Joby Warrick, Alaska Dispatch News, 2 Oct. 2017 Word History
Etymology
German Limonit, from Greek leimōn wet meadow; akin to Greek limnē pool
First Known Use
1823, in the meaning defined above